Maine Economic Improvement Fund

Small Campus Initiative Research

Soft-shell clam research at the University of Maine at Machias

The FY14 Small Campus Initiative (SCI) awards were focused mostly in southern Maine, in Cumberland County, and examined strategies for growing and raising soft-shell clams, Mya arenaria, that were produced at the Downeast Institute (DEI) – University of Maine at Machias’ (UMM) Marine Field Station. The work focused on finding new strategies for managing both wild and cultured clam seed in an environment under severe predation pressure from invasive green crabs, whose populations have exploded recently due to warming trends in seawater temperatures. UMM and DEI are collaborating with a private company, Stewards of the Sea LLC, and the town of Freeport, Maine to examine effects of: sediment buffering on wild clam recruitment; presence of adult soft-shell clams on wild clam recruitment; the combined effect of fencing and netting on growth and survival of cultured clam seed, as well as wild clam recruitment; and the effect of stocking density on cultured clam growth and survival. In addition, two other projects focused on learning about the dynamics of green crabs in selected areas of the upper and lower Harraseeket River in Freeport, and demonstrating the utility of rearing soft-shell clam seed to clammers and local elected officials using a bivalve nursery upweller. The work leveraged a $350,000 grant from the National Marine Fisheries Service, Saltonstall-Kennedy program that will extend the program through 2016.

Maine Maritime Academy’s FY14 MEIF-SCI award is investigating the importance of surplus reproductive material of the two most abundant intertidal rockweeds to nearshore marine environments. In addition, laboratory studies have been examining the response of rockweed reproductive materials on the commercially important blue mussel. During the first year of the grant, field sampling was conducted across three study locations in the Gulf of Maine: Holbrook Island in Penobscot Bay, Schoodic Peninsula in Frenchman’s Bay and Great Wass Island in Western Bay. Laboratory experiments have been completed at Maine Maritime Academy (MMA) and at the Down East Institute Marine Field Station in Beals. Preliminary results of feeding trials using Ascophyllum reproductive material with juvenile mussels showed significantly more growth (metric=shell length) in treatment diets (phytoplankton and a pulse of sperm, egg, or zygote) compared to a control diet of only phytoplankton. Seasonal field sampling of macroinvertebrates has been completed for stable isotope food web characterization and the data are being processed currently. This research has fostered scientific collaboration between MMA, Brian Beal at UMM and the University of Texas at Austin (Dr. Kenneth Dunton, a UMaine alum). It also supported undergraduate research experiences for MMA student Sarah Brochu of Hardwick, Vermont, and UMM students Melissa Burnham of South Portland and Anna Davis of South Addison. Characterizing the timing of reproduction (phenology) of the harvested rockweed, Ascophyllum nodosum, has also led to collaboration between MMA and rockweed business Source Maine, Inc., in Brunswick.